<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>CSS示例</title>
    <link rel="stylesheet" href="style.css">
</head>
<body>
    <p id="p1">1111111111111111111</p>
    <p class="c1" id="p2">2222222222222222222</p>
    <p class="c1" id="p3">3333333333333333333</p>
</body>
</html>